Lamp assemblies are often installed in printed circuits. They are particularly useful in printed circuit boards used for automotive instrument panels, where the lamps provide the light needed to read the instruments and warning telltales. The lamp assembly typically includes a socket and lamp and is designed to install into the instrument panel from the rear and then remain fixed in position.
The difficulty with the "mass production" installation of lamp assemblies into printed circuits is that the conventional lamp socket must be pushed into position in the panel and then rotated to lock the socket onto the panel. Because it is necessary to rotate the lamp socket after insertion, it is more difficult to fully automate the assembly procedure, in that more complex machinery and more time is required to perform the rotation step. Therefore, a lamp socket which does not have to be rotated in order to lock it into place is very desirable in that it reduces assembly time and cost.